Methionine methyl ester

Several cationic palladium(II) aqua complexes, [Pd(H20)4], cis-[PdL(H20)2] (L = en, methionine methyl ester, l,5-dithiacycloocta-3-ol), and [Pd(dien)(H20)], serve as the active catalyst for the selective hydration of various nitriles to the corresponding carboxamides, e.g., CHCI2CN was hydrated to CHCl2C(0)NH2 in the presence of... 

Scheme T. Synthesis of Olefin Isosteres of CaaX Analogues, a) (CH3)2C= CHMgBr b) NaBH4 c) Ac20 d) O3, (CH3)2S e) Ph3P=CHC02 CH3 fl LiOH g) EDC, HOBt, L-methionine methyl ester h) CH3S02Cl /) R2MgCuCNCI-BF3 j) HCI L-N-Boc-S-tritylcysteine aldehyde, NaCNBH3 k) TFA, (QHshSiH I) NaOH.

One-electron oxidation mechanism of methionine methyl ester (MME), N-acetylmethionine (NAM), N-acetylmethionine amide (NAMA), and N-acetylmethionine methyl ester (NAMME) employing OH radicals were studied by means of pulse radiolysis in aqueous solutions. 

Shirdhonkar M, Maity DK, Mohan H, Rao BSM. (2006) Oxidation of methionine methyl ester in aqueous solution A combined pulse radiolysis and quantum chemical study. Chem Phys Lett API 116-123. 

PAME = phenylalanine methyl ester, MME = methionine methyl ester, PME = proline methyl ester, DMPEA = A,a-dimethyl-j3-phenylethylamine. 

Protease mutants were prepared, which showed higher catalytic activity for the enzymatic polymerization of amino acid esters in an aqueous DMF solution. The molecular weight greatly increased by using a subtilisin mutant (subtilisin 8350) derived from BPN (subtilisin from Bacillus amyloliquefa-ciens) via six site-specific mutants (Met 50 Phe, Gly 169 Ala, Asn 76 Asp, Gin 206 Cys, Tyr 217 Lys, and Asp 218 Ser) in the polymerization of L-methionine methyl ester in the aqueous DMF.240 Another mutant (subtilisin 8397), which is the same as 8350 without... 

The reaction was applied to model dipeptides exemplified by the y-phenyl-hydrazide of N-carbobenzoxy-a-L-glutamyl-L-methionine methyl ester (4) and found to afford the carboxylic acid (S) in good yield without disturbance of the carbo-benzoxy and ester protective groups. The results suggest use of the phenylhydrazide group for protection of carboxyl groups in peptide chemistry. 

L-Methionine methyl ester hydrochloride u-Methionine, methyl ester, hydrochloride (2491-18-1), 76, 123... 

A. N-(Benzyloxycarbonyl)-L-wethionine methyl ester 2). A 3-L, three-necked, Morton flask equipped with an efficient mechanical stirrer, thermometer, and a dropping funnel is charged with L-methionine methyl ester hydrochloride (117.6 g,... 

A. Methyl (S)-2-phthalimido-4-methylthiobutanoate. Into a 2-L, round-bottomed flask fitted with a Dean-Stark apparatus, reflux condenser, and drying tube containing calcium chloride are placed L-methionine methyl ester hydrochloride (50.0 g, 0.25 mol, Notes 1 and 2), phthalic anhydride (37.1 g, 0.25 mol), triethylamine (100 mL, 0.72 mol), and toluene (1 L). The mixture is magnetically stirred and heated under reflux for 4.5 hr at which point approximately 4.5 mL of water has separated. The reaction mixture is allowed to cool to room temperature and the precipitated triethylamine hydrochloride (34 g) is collected by suction filtration. The filtrate is washed with four 300-mL portions of 1 N aqueous hydrochloric acid followed by three 300-mL portions... 

Commercial L-methionine methyl ester hydrochloride (from Aldrich Chemical Company, Inc.) is used or can be easily prepared using a literature procedure.2... 

The (R)-aldehyde could be prepared from the hydrochloride salt of D-methionine methyl ester using a similar two-step procedure. 

Methyl (S)-2-phthalimido-4-methylthiobutanoate 2H-lsoindole-2-acetic acid, 1,3-dihydro-a-[2-(methylthio)ethyll-1,3-dioxo-, methyl ester, (S)- (9) (39739-05-4) L-Methionine methyl ester hydrochloride Methionine, methyl ester, hydrochloride, L-(8) L-Methionine, methyl ester, hydrochloride (9) (2491-18-1)... 

Methionine-enriched protein was produced also from an enzymatically prehydrolyzed milk protein using an enzymatic peptide modification method with a-chymotrypsin as catalyst. Amino acid incorporation leading to methionine enrichment of the product proceeded via formation of covalent bonds. The concentration of the substrate was 25% (w/v). Methionine was added to the reaction mixture in the form of methionine methyl ester hydrochloride. An ester/substrate ratio of 1 5 was used in the enzymatic peptide modification reaction. The methionine content of the product was twice as high as that of the substrate. The slight change in the degree of hydrolysis revealed that part of the amino acids were bound to the peptide chains and that transpeptidation was the main force during this enzyme-catalyzed reaction. The newly incorporated Met was located in C- and N-termi-nals in a ratio of 3 1 [82],... 

Functional properties of some enzymatically modified and EPM-treated products of milk proteins [136] were determined as follows. An enzymatically prehydrolyzed commercial milk protein concentrate (SR) without further hydrolysis, and casein hydrolyzed by alcalase, a-chymotrypsin, and papain, respectively, were used as substrates in the EPM reaction. The concentration of the hydrolysates was 20% w/ v in the EPM reactions. A methionine methyl ester hydrochloride/ substrate ratio of 1 5 was used for incorporating this amino acid. After incubation, the products with methionine incorporation were simultaneously dialyzed for 2 days through a cellophane membrane against distilled water. The nondialyzable fractions and the EPM products without amino acid enrichment were freeze-dried. Covalent methionine incorporation in the EPM products with amino acid enrichment was verified by exopeptidase hydrolysis of the protein chains. The functional properties of the different EPM products are summarized in Table 1. An important functional property of proteins and/or peptide mixtures is their emulsifying behavior. This is highly influenced by the molecular structure, the position and ratio of hydrophobic-hydrophilic amino acids. Emulsion activity was found to be low (34.0) for casein, and the values determined for enzyme hydrolyzed and modified products were in general even lower. The papain hydrolysate, sample H3, showed here a different behavior as well this was the one of the sample series that had the highest EAI value (43.0). The emulsion stability of the enzymatically modified products displayed tendencies quite opposite to the values of emul-... 

A. N-(Benzyloxycarbonyl)-L-methionine methyl ester (2). A 3-L, three-necked, Morton flask equipped with an efficient mechanical stirrer, thermometer, and a dropping funnel is charged with L-methionine methyl ester hydrochloride (117.6 g, 0,66 mol) (Note 1), potassium bicarbonate (282.3 g, 2.82 mol, 500 mol %), water (750 WL), and ether (750 mL), and the solution is cooled to 0°C. Benzyl chloroformate (105... 

N-(Benzyloxycarbonyl)-L-vinylglycine methyl ester 3-Butenoic acid, 2-[[(phenylmethoxy)carbonyl]amino]-, methyl ester, (S)- (10) (75266-40-9) N-(Benzyloxycarbonyl)-L-methionine methyl ester L-Methionine, N-[(phenylmethoxy)carbonyl]-, methyl ester (9) (56762-93-7)... 

The kinetics of substitution of L on 7roKs-[Ru(S03)(NH3)4(0H2)] have been reported Table 4) and indicate that replacement of NHj by SO," lowers the affinity for the incoming ligand approximately ten-fold, but increases the rate of substitution approximately 100-fold, a much greater lowering of affinity being observed with methionine methyl ester. Reaction of [Ru(NH3)5(OH2)] with P(OEt)3 in acetone gives [Ru(NH3)4(P(OEt)3)2p from which the derivatives trans-[RuL(N-H3)4(P(OEt)3)] could be prepared for aquation (L = H2O) of the diphosphite complex the rate... 

---